Do so many people actually click on ads? On sites like Facebook? Yes. There's a lot of criticism, much of it justified, about spammy ads online. However, with

Do so many people actually click on ads? On sites like Facebook? Yes. There's a lot of criticism, much of it justified, about spammy ads online. However, with a system like Facebook's or something like a search engine, the ads being shown are normally for something that might genuinely interest the viewer. That makes a favourable reaction much more likely, and it means far fewer resources are wasted showing ads to people who aren't likely to be interested.